Method and apparatus for cutting sheet glass

ABSTRACT

The present invention relates to a method of cutting a sheet glass wherein the surface of a sheet glass is scored in advance with cutting lines on the surface thereof and is carried by a first conveyor system. The sheet is subjected to an almost uniform fluid pressure applied thereto in front and in the rear of a cutting roll disposed adjacent to and at a level not lower than the terminal end of the first conveyor system. When a cutting line scored on said sheet glass is positioned adjacent the top of the periphery of said cutting roll, a part of the sheet glass in front of the cutting roll, which works as a fulcrum, is bent downwardly by the pressure and broken along said cutting line. The pressure fluid is supplied from a fluid supply source via a supply pipe and is jetted from jet-nozzles opening at the bottom of a fluid-jetting device connected to one end of said supply pipe.

United States Patent Simomura [451 Sept. 26, 1972 [72] Inventor: Katsuyasu Mieken,

Japan [73] Assignee: Central Glass Co., Ltd., Ube-shi,

Yamaguchi-ken, Japan 22 Filed: o.3o,197o

21 Appl. No.: 85,542

Simomura,

[30] Foreign Application Priority Data Dec. 1, 1969 Japan ..44/96406 [52] US. Cl. ..225/4, 225/2, 225/93,

[51] Int. Cl. ..B26f 3/00 [58] Field of Search ..225/2, 4, 93, 96.5

[56] References Cited UNITED STATES PATENTS 2,316,532 4/1943 Owen ..225/93 3,517,869 6/1970 Dryon ..225/96.5 X

Primary Examiner-Frank T. Yost Attorney-Woodhams, Blanchard and Flynn [57] ABSTRACT The present invention relates to a method of cutting a sheet glass wherein the surface of a sheet glass is scored in advance with cutting lines on the surface thereof and is carried by a first conveyor system. The sheet is subjected to an almost uniform fluid pressure applied thereto in front and in the rear of a cutting roll disposed adjacent to and at a level not lower than the terminal end of the first conveyor system. When a cutting line scored on said sheet glass is positioned adjacent the top of the periphery of said cutting roll, a part of the sheet glass in front of the cutting roll, which works as a fulcrum, is bent downwardly by the pressure and broken along said cutting line. The pressure fluid is supplied from a fluid supply source via a supply pipe and is jetted from jet-nozzles opening at the bottom of a fluid-jetting device connected to one end of said supply pipe.

5 Claims, 3 Drawing Figures METHOD AND APPARATUS FOR CUTTING SHEET GLASS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of and an apparatus for cutting sheet glass belt, as it is being conveyed without interruption, along the'cutting a line scored in advance on a surface thereof, by means of jetting a fluid on said surface.

2. Description of the Prior Art A means currently popular in cutting asheet glass while its being conveyed comprises the steps of providing the surface of the sheet glass with cutting lines perpendicular to the direction of the movement at intervals equivalent to the desired length by employing a cutting-line scoring device; and subjecting the sheet glass, as it is being moved by employing a conveying device such as a roll conveyor, to upwardor downward pressure applied thereto near the cutting line by pressing a pressure rubber-roll disposed either on the top or at the bottom of the conveyor against the sheet glass, thereby breaking it along said cutting line. This means, however, has been accompanied by the drawbacks that failure to apply pressure with the pressure rubber-roll precisely along the cutting line may result in an irregularity of the cut end and, therefore, it is very difficult to ensure the exact timing for application of the pressure.

To make up for said drawbacks, there has also been adopted a measure that the cutting line is detected by means of an appropriate electrical or mechanical detection device and the pressure rubber-roll is operated according to signals given by the detector. But, employment of such a measure has been accompanied by the drawback that the apparatus required therefor is intricate and is very costly.

To eliminate said drawbacks, there is currently practiced another means wherein the pressure rubber-roll is so devised as to press the sheet glass constantly. But,

this means has also a drawback such that the fine cullet and other alien substances arising from the cutting operation get in between the sheet glass and pressure rubber-roll, resulting in scratches on the surface of the sheet glass due to friction.

Besides, varieties of means utilizing such a pressure rubber-roll as stated above are apt to subject the surface of sheet glass to a linearly or dottedly concentrated load by means of said rubber-roll, thereby rendering the load on the sheet glass uneven, and, accordingly, they have been accompanied by such drawbacks that the cut ends of the sheet glass thus broken get ragged, resulting in the decrease in commercial value of said sheet glass or yield of products.

Accordingly, it is an object of the present invention to provide: I

l. A method of and an apparatus for cutting a sheet glass along the cutting line provided thereon in advance, by applying fluid pressure;

2. A method and apparatus for cutting a sheet glass as aforesaid, wherein said cutting is effected, while the sheet glass scored in advance with cutting lines is being conveyed with a conveyoer, along said cutting lines by 'virtue of fluid pressure applied onto the surface of said sheet glass;

3. A method and apparatus for cutting a sheet glass as aforesaid, wherein said cutting is effected without employing any device for detecting said cutting lines;

4. A method and apparatus for cutting a sheet glass as aforesaid, wherein said cutting is effected, while the sheet glass scored in advance with cutting lines is being moved with a conveyer under a fluid flow being constantly jetted downwards, along said cutting lines by virtue of fluid pressure applied onto the surface of the sheet glass;

5. A method and apparatus for cutting a sheet. glass as aforesaid capable of producing linear cut ends, wherein fluid is jetted onto the surface of the sheet glass in front and in the 'rear of a cutting roll mounted on the conveyer by disposing perpendicularly relative to the direction of movementof the sheet glass and pervading almost uniformly all over the surface of the piece of sheet glass to be cut off;

6. A method and'apparatus for cutting a sheet glass as aforesaid, wherein the fluid which is jetted onto the surface of the sheet glass is capable of sweeping alien substances off the surface of the sheet glass;

7. A method and apparatus for cutting a sheet glass as aforesaid, wherein said cutting is effected along said cutting lines by virtue of low pressure air being jetted onto the surface of the sheet glass and imposing a necessary load thereon; and

8. A method and apparatus for cutting a sheet glass as aforesaid, wherein without causing scratches on the surface of the sheet glass by virtue of low-pressure air being jetted onto the surface of the sheet glass and imposing a necessary load thereon.

Other objects and purposes of the present invention will be apparent to persons acquainted with apparatus of this general type'upon reading the following specification and inspecting the accompanying drawings.

SUMMARY OF THE INVENTION In general, the objects of the present invention can be achieved by applying a method of cutting a sheet glass comprising the steps of subjecting a sheet glass scored in advance with cutting lines, while it is being conveyed by a conveyer system, to the pressure of a fluid jetted onto the surface of the sheet glass in front and in the rear of a cutting roll disposed perpendicular to the direction of movement of the sheet glass; and, at the time when a cutting line-is positioned adjacent the top of the periphery of the cutting roll, bending the part of sheet glass in front of said cutting line downwards, using the cutting roll as a fulcrum, by virtue of said fluid pressure applied uniformly thereon, resulting in breaking of the sheet glass along the cutting line, and an apparatus for use in said method.

As for the aforesaid apparatus, reference is made to the appended drawings, viz. a schematic representation the apparatus which may be utilized in practicing one embodiment of the present invention.

In brief, the conveyer system comprises a first roll conveyer, and. the cutting roll is disposed at the terminal of and higher than this roll conveyer. Adjacent the cutting roll, there is installed a second roll conveyer which runs swifter than said first roll conveyer. A fluid supply system is so devised as to stretch over the ends of the two roll conveyers adjoining each other across the cutting roll, and it consists of a jet-box having a plurality of jet-nozzles located near the edge of its bedplate, a blast pipe whose one end is connected to the opening of the ceiling wall of said jet-box, and an air blowerconnected to. the other end of said blast pipe. The foregoing jet-box is so devised that its position may be adjusted inaccordarice with the size of sheet glass to ensure that the cutting line of the sheet glass is located near the top of the periphery of the aforesaid cutting roll when the front'edge of the'sheet glass has reached the position corresponding to the foremost jet-nozzles above the second roll convey'er.

' locked in position by means of the screw rod 22.

'Scoring of the cutting lines on the sheet glass is usually effected. by employinga conventional scoring device, and the sheet glass thus provided with cutting lines is carried by the roll conveyor to move forward under the fluid-jetting nozzles, and, after passing the cutting roll, it keeps moving .while slowly approaching the foremost jet-nozzles. Inthe meantime, a fluid is constantly jetted from. the jet-nozzles onto the surface of the sheet glass, whereby there is formed a fluid layer having almost Iuniform pressure upon the surface area of the sheet glass confined by the'jet-nozzles. The load upon the surface of the sheet glass imposed by this fluid layer increases little by little as the sheet glass moves forward, and, when 'thefront edge has reached a position' near the foremost jet-nozzles or just beyond said jet-nozzles, it rapidly increases up to the peak thereof. At this moment, a cutting line is located approximately atop the cutting roll, and the aforesaid load works to bend downwardly the sheet glass in front of said cutting roll which functions as afulcrum, thereby causing the sheet glass to break along the cutting line.

BRIEF DESCRIPTION OF THE DRAWINGS HO. 1 shows an oblique section 'of an apparatus embodying'the present invention.

FIG. 2-is a partial cross-sectional view taken along the II-Il lineshown in FIG. 3, of the same apparatus as shown in FIG. 1. s

FIG. 3 is a cross-section taken along the Ill-Ill line shown in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION front end of the machine-frame 15 by employing the adjusting screw 19 so asto permit vertical movement of said cutting roll, and a sprocket is fixed on one end of the shaft of said cutting roll 3. The chain 20 is laid on all sprockets, and, by operating'this chain 20 with a driving gear (not shown in thedrawings), the rolls 2 and 3 are made to rotate.

The roll is supported by means of the-bearing 16' fixed on the machine-frame installed in front of the machine-frame l5, and the'chain islaid on the sprocket 17' fixed on one end of this roll 5. By operating this chain 20 faster than the foregoing chain 20 with a driving gear (not shown in the drawings). the roll 5 is made to rotate faster than the rolls 2 and 3.

The'opposite edges of the under side of the square supporting-plate 6 are fixed on the supporting rods 7, and the opening provided in the center of said plate is connected to the foremost end of the blast pipe 13,

while the rearmost end of said blast pipe 13 is connected to the exhaust pipe provided for the air blower 1 1 having the damper 12. The jet-box 23 is perpendicularly fixed on the under side of the supporting plate 6. The jet-box 23 is provided with a plurality of jet-noz zles 24 opening aslant and downwards in a rectangular pattern. The bottom wall within the jet-box is provided with the cone-shaped flow-adjusting protuberance '25, and the ribs 26 connect the .innerand outer frames of the jet-box 23 for the purpose of forming the jet-nozzles 24 and also to regulate the jetting fluid.

Next, the process of cutting a sheet glass by employing the aforesaid apparatus will be discussed in the following;

To begin with, by loosening the screw rod 22, the supporting rod 7 is moved forwards or backwards relative. to the cradle rods 8 and 8' so as to make the horizontal distance between the foremost jet-nozzles 24 located above the roll 5 and the top of the'periphery of the cutting roll 3 and the desired length of sheet glass to be cut almost equal, whereby the position of the jetbox 23 is adjusted.

When the sheet glass 1 provided with cutting line 14 previously scored perpendicular to the direction of foremost end draws near the jet-box 23.

Meanwhile, the jet-nozzles 24 disposed on the under side of the jet-box 23 jet the air supplied by the air blower l l, and the currents of jetted air strike against a square area of the surface of the sheet glass 1 extending from thefront to the rear of the cutting-roll 3 and form an air layer having an almost uniform pressure upon the surface of the sheet glass. The amount of the air to be jetted on this occasion is regulated by the damper l2, and this air strikes against the flow-adjusting protuberance 25 as soon as it comes out from the blast pipe 13 and is thereby distributed almost uniformly to the sur rounding jet-nozzles 24;-

Under the foregoing circumstances, the front end of the sheet glass 1 keeps progressing little by little as it approaches to the under side of the jet-box 23 nearer than the hind part of said sheet glass, and, with such progress, the load on the surface of the sheet glass imposed by the jetting air increases little by little until the front end of the sheet glass reaches to a position near or beyond the foremost jet-nozzles 24 whereat said load increases rapidly up to the maximum.

At this moment, the cutting line 14 on the sheet glass 1 is located near the top of the periphery of the cutting roll 3, and, as a result, the part of the sheet glass in front of the cutting line 14, namely, the sheet glass 1' is bent downwardly under pressure of the jetting air as the cutting roll 3 works as a fulcrum, and is thereby broken along the cutting line 14 in such a fashion as shown by the diagram 1 drawn with broken lines in FIG. 3.

The sheet glass 1' thus cut off is laid on the roll 5, and, as this roll 5 is being operated faster than the roll 2 as set forth above, said sheet glass 1 is rapidly disconnected from the succeeding sheet glass 1 and is conveyed forward.

The fine cullet and other alien substances arising from the cutting operation are blown off the surface of the sheet glass by the jetting air-current and said surface is cleaned up. The surface of the cutting roll 2 is always swept off by the brushing roll 4 and is kept clean, thereby preventing the under side of the sheet glass from getting scratched.

Subsequent to the transfer of the sheet glass 1' cut off as above, the space which has been occupied by the sheet glass 1 is abruptly left open, resulting in a prompt decrease in air pressure to be followed by a temporary decrease in the load upon the sheet glass 1 succeeding thereto.

The present apparatus is, therefore, capable of assuming a posture of standing by to work on the succeeding sheet glass 1 and perform the cutting operation in succession in the same manner as above.

Although particularly preferred embodiments of the invention have been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof which lie within the scope of the appended claims are fully contemplated.

For instance, although there has been employed air as the applicable fluid in the present embodiment, said air may be replaced by another gas or liquid. Although the jet-nozzles 24 are quadrately disposed near the bottom of the jet-box 23 in the present embodiment, it will also do to dispose them in parallel along the front and rear sides only. Although the rolls 2 are all disposed on one and the same horizontal level in the present embodiment, it will also do to elevate them gradually toward the cutting roll 3 so that they constitute en bloc one roll conveyer having an inclination in the direction of the cutting roll 3, or to dispose them on the same horizontal level as the cutting roll 3, or to modify the roll conveyer comprising the rolls 2 and 3 to a belt conveyer.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A method of cutting a sheet glass in the course of conveying same when the sheet has been scored in advance with cutting lines, which comprises the steps of: providing a cutting roll on the conveying path of the sheet glass disposed substantially perpendicularly relative to the direction of movement of the sheet; and subjecting the surface of the sheet glass as it moves along the path to a substantially uniform fluid pressure applied thereon by jetting a fluid in front and in the rear of said cutting roll at the time when a cutting line on the sheet glass is located adjacent the top of the periphery of the cutting roll, wherebgthe part of the sheet glass in front of the cutting roll, w ich acts as a fulcrum, is bent downwards and broken along said cutting line.

2. A method as defined in claim 1, wherein said fluid comprises air.

3. An apparatus for use in cutting a sheet glass, which comprises: a first conveyer system for carrying the sheet glass; a cutting roll disposed adjacent to and at a level not lower than the terminal end of the first conveyer system; a second conveyer system disposed adjacent to and at a level lower than the aforesaid cutting roll; a fluid-jetting device installed above a part of the foregoing two conveyer systems as well as above said cutting roll for jetting a fluid downwardly onto the sheet glass as it passes over the cutting roll; a fluid supply pipe having one end connected to the fluidjetting device; and a fluid supply source connected to the other end of said fluid supply pipe.

4. An apparatus as defined in claim 3, wherein said first and second conveyer systems comprise first and second individual roll conveyers, respectively, and means for driving the second roll conveyer faster than the first roll conveyer.

5. An apparatus as defined in claim 3, wherein said fluid-jetting device comprises a jet-box provided with oppositely sloped jet-nozzles disposed near the opposite edges of the under side thereof. 

1. A method of cutting a sheet glass in the course of conveying same when the sheet has been scored in advance with cutting lines, which comprises the steps of: providing a cutting roll on the conveying path of the sheet glass disposed substantially perpendicularly relative to the direction of movement of the sheet; and subjecting the surface of the sheet glass as it moves along the path to a substantially uniform fluid pressure applied thereon by jetting a fluid in front and in the rear of said cutting roll at the time when a cutting line on the sheet glass is located adjacent the top of the periphery of the cutting roll, whereby the part of the sheet glass in front of the cutting roll, which acts as a fulcrum, is bent downwards and broken along said cutting line.
 2. A method as defined in claim 1, wherein said fluid comprises air.
 3. An apparatus for use in cutting a sheet glass, which comprises: a first conveyer system for carrying the sheet glass; a cutting roll disposed adjacent to and at a level not lower than the terminal end of the first conveyer system; a second conveyer system disposed adjacent to and at a level lower than the aforesaid cutting roll; a fluid-jetting device installed above a part of the foregoing two conveyer systems as well as above said cutting roll for jetting a fluid downwardly onto the sheet glass as it passes over the cutting roll; a fluid supply pipe having one end connected to the fluid-jetting device; and a fluid supply source connected to the other end of said fluid supply pipe.
 4. An apparatus as defined in claim 3, wherein said first and second conveyer systems comprise first and second individual roll conveyers, respectively, and means for driving the second roll conveyer faster than the first roll conveyer.
 5. An apparatus as defined in claim 3, wherein said fluid-jetting device comprises a jet-box provided with oppositely sloped jet-nozzles disposed near the opposite edges of the under side thereof. 